一种基于小波变换的水印嵌入算法

在充分考虑人眼视觉系统的基础上,提出一种基于小波变换的水印嵌入算法,首先在嵌入水印时,将宿主图像作适当层次的二维小波分解,分解出高频边缘等细节信息,然后对以低频信息为主的小波逼近子图再作二维DCT,将水印信息嵌入到DCT的低频和中频系数中.考虑到灰度水印嵌入的水印信息量大,除了在小波逼近子图嵌入数据外,通过合理设计强度因子,在高频带也嵌入部分数据.在基本不影响水印透明性的情况下最大化嵌入水印的强度和信息量.实验结果表明,应用本算法对常见的图像处理和噪声干扰具有很好的鲁棒性.

A Watermark Embedding Algorithm Based on Wavelet Transform

By taking the human visual system into account,the paper proposes a new algorithm of digital image watermarking based on discrete wavelet transform.First,it proposes the dimension-wavelet decomposition of the host image embedded in watermark,and decomposes the detailed information of the high frequencies.Secondly,Discrete Cosine Transform(DCT) of the wavelet approximate sub-images which are mainly low frequency information is made,and consequently the watermark is embedded in low frequency and middle freque...